A portcullis is a heavy metal grille, used to bar the gateway of a castle. It’s a period charge, found in the arms of Fyschcok, c.1480 [RH], but more famous as the badge of Beaufort, 1449, from whom the Tudor kings inherited it [Parker 473; HB 143, 111].
In period, English emblazons showed the portcullis with its chains on either side, hanging to base (as in the illustration); these need not be blazoned. There are some examples in Continental heraldry of chainless portcullises, such as the arms of Hessen zu Wigdorf, 1605 [Siebmacher 136]; chainless portcullises in Society armory should be explicitly blazoned.
Ernst of the Gate bears: Per pale Or and sable, a portcullis gules.
Alexis Sinclaire bears: Sable, three portcullises Or.
Almarr of Odder bears: Azure, three portcullises argent.